This invention relates to means for assuring discrete pin alignment in a cathode ray tube-base assembly and more particularly to means for achieving alignment of at least one CRT pin spatially encompassed within a substantially tubular, pin isolating means of the associated base member.
The advance of cathode ray tube technology, in particular, the tube types employed in color television applications, has resulted in the development of more compact electron gun structures evidencing greater efficiencies. These smaller-in-size guns, being oriented within tube envelope neck portions of reduced diameter, have the necessary operating voltages for the various elements thereof (heaters, cathodes, accelerating and focusing electrodes, etc.) supplied via an annular array of connector pins sealed into and projecting from the stem closure portion of the tube. As the neck diameters of the tube envelopes become smaller, the spacings between the connector pins likewise decrease.
Certain currently produced tubes have large voltage differentials between certain of the pins in the connector array. This differential, sometimes in the order of 5 KV to 12 KV, has necessitated the incorporation of some form of arc protection into the tube base and socket combination. Bases and sockets have been designed in the art to minimize inter-pin arcing wherein at least one of the vulnerable high voltage pins is tubularly encompassed by a spatially related isolation structure integrally formed as part of the base member. In conjunction therewith, a compatible socket member has receiving means to mate with the respective tubularly encompassed pin, thereby effecting an isolated high voltage connection. While this type of connection has been found to be very beneficial, its advantages have been overshadowed by the fact that if the pin, positioned within the protective tubulation, becomes bent out of alignment, during tube basing or as a result of subsequent tube mishandling, here is no easy way of straightening the pin due to the narrow dimensioning of the surrounding tubulation. Consequently, before the tube can be used, the base must be removed, the pin straightened and another base applied. This becomes a tedious and time-consuming procedure, since the base is usually affixed to the tube by a tenacious adhesive composition. There is also a danger of tube implosion during the tube de-basing operation.